YDL3 and iMac CDROM Drives

[Tim Seufert]

On Saturday, May 10, 2003, at 12:15  PM, Jeremy R. Gilby wrote:

> (I could "shove" the drive back in, but that just spells future
> mechanical failure)

No, it doesn't.  Just gently but firmly press on the tray until the 
drive senses it and pulls the tray in.  They're designed for it.  The 
only way you can break them by doing it is if you use excessive force.  
The drive is already exerting considerable force on the tray, because 
they usually just stall the DC motor that moves the tray in and out.  
(DC motors develop maximum torque when stalled.)  When you push on the 
tray (against the motor), the motor driver IC observes increased 
current demand by the motor, and the drive uses that as a sign that 
it's time to pull the tray in.  All this stuff is overdesigned to the 
point that it cannot be hurt by normal operations, including pushing 
back on the tray.

If you push hard enough that you feel and hear gears slip, that's too 
much force.  But you'd have to push really hard really fast to make the 
gearing slip before the drive sucks the tray back in on its own.  Even 
if you did manage to do it, the gears are always nylon with fairly 
sloppy tolerance so they are not going to be stripped by one or two 
gear grinding incidents.